How long can a bacterial culture be storage be stored at 4 degrees? - (Jun/30/2008 )

How long can a bacterial culture be storage be stored at 4 degrees?
either in LB or agar plate

I know the best long term storage is in glycerol stock at -70. Just want to know.
because eg when making a small-volume culture for mini-prep for example, I usually storage those left-behind culture at 4 degrees for a period. In case I screw up my mini , I have something backup and don't need to grow the culture again. However I really don't know how long can the culture be stored in this way. Different ppl in my lab have different opinions

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I am sure that would be the case here too..

In my experience, I have revived colonies as old as 2 months. But it depends upon so many factors that I don't want to list them all here.

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This really depends on how you store it and how careful you are, with parafilm around the plate I have used it up to two months as well. But some of my colleagues will have contamination within a few weeks. So it really depends. Some constructs won't hold with long time storing in 4C so keep that in mind too.

Hope this helps.

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its possible to store them up to a year.
But instead of storing them in LB (liquid broth?) or on agar plates, you better use demineralised sterile water.

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I really don't think storing them in demineralised sterile water will do good. ( i assume by demineralised u mean distilled ?!)
One year is really a wild guess right there. Most i say is 1 month but that might not even be a good estimate , Different strains of bacteria gives different "shelf life" that much is true. For E.coli, yea they pretty cool with 1-3 months i have seen them recover before after so long sticking in the fridge. But for other bacteria u might wanna be careful, they might not last that long.

P/S : it's really hard to screw up a mini esp if it's E.coli u're dealing with .

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No I really mean demineralized water that has been sterilised by autoclaving and then the bacteria sample added to the tube with demineralized water.
if you place them on a broth they will "kill" themself by poluting the media they stay in (they stay active and "eat" the media and produce toxics.... when using the water they go into hypobiosis or even anabiosis, however they do still grow at the start, so you might wanna lower your temperature.

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Yeah,it's true that some strains are fit for storing in demineralised sterile water, though storing on a broth is more traditional.

How long can a bacterial culture be storage depends on the strain of the bacterial, and normally, 2-3 months.

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Is demineralized water isotonic for the bacteria, looks like distilled water to me.

would it be better to use saline instead?

But seriously for storing i like to make everything on agar plate because
1. easier to streak out.
2. u won't break any glass or spill anything
3. important: on agar u can tell if there's any contamination , on broth/ water , it's hard to tell just by visual judment unless the contaminant are really different from the original strain ( fungus vs bacteria) or other other cases .

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BTW,

sometimes bacteria cultures eliminate their plasmids, if the antibiotics decline with the time. The plasmids are then useless or interfering and bacteria can get rid of them. For longer storage I freeze them in a glycerol-stock.

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Agree. If you want to have a better yield of your plasmid, don't put the culture in the frige for more than 2~3 days. Of course, the period really depends on the strain, vector and the antibiotic

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